Fused connector



April 1941; w. J. P. STONEHOUSE 2,240,080

FUSED CONNECTOR Filed June 20, 1939 Patented Apr. 29, 1941 FUSED CONNECTOR William James Peter Stonehouse, Richmond, Victoria, Australia Application June 20, 1939, Serial No. 280,028 In Australia June, 29, 1938 3 Claims.

An object of this invention which relates to electric sockets and power outlets usable for example for attachment of domestic and some other electric lamps, is to provide devices whereby no materially higher power may be taken therethrough than would suit a predetermined use of the sockets in such a case as where a landlord installs sockets which he intends shall be usable only for lamps, and charges for the use of electricity on that basis; that is that the sockets will not be used for connection of attachments for heating, ironing, and so forth, whereby heavier current would be consumed than in the case intended as stated.

A further object of my invention is to combine electric fuses in a novel and useful manner with other parts of lamp holders or sockets, ceiling roses, and power plugs-that is outlets for electric current, all these herein, for brevity, being covered by the term socket-whereby the sockets are economical by preventing use therewith of any electrical appliances which would consume current in excess of a maximum predetermined amperage in relation to the sockets.

All appliances may with my invention be used provided they do not consume above the said maximum.

Various advantages and other effects of the use of this invention will be apparent from the following.

I provide in the socket a controlling or load limiting fuse, the presence of whichis all-important. If, for example, it allows consumption up to, but not above 300 watts, then if that be exceeded by the current, the fuse would burn out, and break the circuit, and the attachment, such as a heater, would not receive current even if the lamp, for example, could take in excess of that limit if supplied therewith.

But I make no claim broadly to using such a fuse, as, for other purposes and in other constructions than mine, fuses are provided on switchboards at entrances to buildings, and elsewhere, which limit the current usable, but differ from my device, for example by allowing relatively heavy current to pass to a series of fuseless sockets and allowing higher loading of individual sockets of the series than is predetermined in my case for individual sockets. These known sockets are not therefore, as in my case, all individually economical.

Herewith is a drawing which illustrates applications of this invention, though the latter is not limited to such details shown as are obviously, to those skilled in the art, variable within the scope of my claims.

Figure 1 shows in vertical section one of my improved sockets.

Figure 2 shows in vertical section the socket of Figure 1, fitted with electrical conducting wires and an electric lamp, the lower part of which is not shown.

Figure 3 illustrates, in section, a power plug of two round pin type-a known fitting being shown, with my additions.

Figure 4 illustrates in section a power plug of three fiat pin type, a known fitting being shown, with my additions.

Figure 5 is a plan on line 55 of Figure 3 excluding the lead C, the fuse, and the securing screw V.

Figure 6 is a sectional plan on line 66 of Figure 4 excluding the lead C, the fuse, and the securing screw V.

Figure 7 illustrates the construction in Figures 1 and 2 modified to suit a socket to which the fitting for current consumption is screwed.

In these illustrations A indicates the upper part of an electric lamp, having means shown by pins A by which to attach or connect itto a socket, as to the hollow circular base B of said socket, B being any suitable means-as ordinary bayonet slots-to receive said pins. C is the active conducting wire, and C the neutral conducting wire, both entering a casing or cover D through, for example, a hole D member D being removable to allow of attention to internal parts. It is shown screwed at D on a screw threaded head 13 which carries base B, that head being shown fitted with an ordinary adjustable shade-holding ring F.

Projecting into the space within end B are terminals E (one shown in Figure l) with which the head of lamp A makes the usual contacts.

As a fuse I provide a short length of wire or material H having a suitably low melting or destruction temperature. This wire is carried by or mounted on a spacer H of nonconducting material which has means to hold the wire extended, as end caps H (under which the wire ends are gripped) of metal. The spacer is on the active side of the socket, and in some cases I make it readily replaceable or changeable by any careful intelligent user; but in other cases I arrange it so that it would not be easily tampered with or be changed by an unskilled person. I provide for example for setting a seal or a keyless or other lock on the socket. Thus there are in Figure 3 lugs with eyes T, T on parts to be sealed or locked together. The neutral and active wires should be tested to ensure .correctness. If the fuse were on the neutral wire, and if the fuse broke down through over load, the appliance would remain electrically alive at the active terminal, and would not usually be safe to handle.

With my device in the form illustrated, the attached appliance can be safely handled in a case of fusing: the socket itself can also be safely handled.

The fuse spacer H, in Figure 1, is positioned by setting its lower end securely in a recess or housing in the head J of a conductor rod J of the socket, the head being conveniently of greater diameter than the rod body. At the base of rod J is the terminal E. The fuse top becomes thus a lower contact by which the circuit may be established. At a suitable distance above this fuse, and thus above the conductor rod J (which is fitted with the usual depression spring K) is a conductor rod 0.

M shows the active terminal to which a conducting wire C is secured. The socket contains an elongated partition N between the active and neutral sides, and N shows a flange on or offset from this wall, there being an aperture N to house the upper part of red O, which is normally depressed by, for example, a spring 0 which has a suitable abutment, as nut O screwed on rod O. The partition and its offset are of non-conducting material.

On the neutral side, the terminal conductor P has wire C attached.

When the socket described is not fitted with a lamp (or adapter) its contacts E are spring depressed, and the fuse is also lowered clear of rod 0 leaving the socket dead, and the circuit open, so that the action is that of a switch.

Active terminal M is secured on the rod 0 next 1 to partition oifset N and wire C is held, as by a screw M The bottom of conductor 0 may be slightly hollowed to ensure good contact with the fuse top when the fuse is pressed upward as next explained.

When the lamp is inserted in the socket it forces rods J upwards, and consequently also raises the fuse which meets and presses the conductor rod or plunger 0 with which the active wire C is in electrical connection. I provide in some cases, for the application of a seal in or on casing D, or a lock is fitted, so that the fuse will be safeguarded against tampering. I provide that fuses can be changed to allow of their use to suit predetermined maximum strengths of current, and so that for fuses burned out, others may be substituted.

Parts in Figure 7, not previously illustrated, are a contactstrip or tongue E extending from rod J and connecting with a central contact member E of the attachment A The threaded skirt B of the socket, is connected to the return lead. The active electric lead becomes operative when rod J with fuse cap H engages rod 0.

Figure 3 shows an addition Y to the known upper part Z of Figure 3. I connect the neutral wire C through this addition to the existing terminal U having a holding screw U in Figure 3, and I connect the active wire 0 to a block R securing the wire terminal in a. recess R of the block. One end of the fuse carrier H already de- F scribed, fits into a second recess R in this terminal block, said recess R housing a spring S bearing on the fuse carrier. The addition Y shown separately in Figure 5 is united with the upper part Z shown in Figure 3, as by a long screw V.

Z and Z are ordinary pin receptacles provided in the fitting here shown.

The fuse contacts with the plug terminal-- which has no wire holding screw such as U.

Figure 6 shows my addition W to be attached to a conventional three-flat-pin receptacle X shown at the upper part of Figure 4. In this case, a spring S is located above and depresses the fuse carrier H. The usual contact terminal provides space for this arrangement. As in Figures 3 and 5, the active wire C connects into the terminal block R at R and the end of fuse carrier H rests in the aperture R Addition W is secured by a long screw shown at V which holds the parts together as a unit. X and X in Figure 4 correspond to parts Z and Z in Figure 3.

My construction will also have the desired preventive effect if there be attached to the socket a lamp consuming higher power than is predetermined.

Some electric sockets are made with one or more branches so as to carry one or more lamps or current receiving connections, and in such cases I apply in the circuit of each receiver a fuse as described. In such cases the fuses will be used of respective current capacities suited to the intended uses of the respective outlets of the socket.

I claim:

1. In a fused outlet device, a housing, active and neutral terminals in said housing, a member secured to said housing and including a sleeve communicating with said housing and adapted to receive a contact element of an electric appliance to be connected to said outlet, an insulating bracket between said active terminal and said sleeve, a contact piece disposed slidab'ly in a bore extending through said bracket, a fuse mounted on the inner end of said contact piece and proiecting towards said active terminal, and a spring supported on said bracket and acting on said contact piece to urge the latter into a position in which its outer end projects into said sleeve and said fuse is spaced from said active terminal, the fuse being brought into contact with said active terminal when the contact element of said electrical appliance is introduced into said sleeve.

2. A fused outlet device, as claimed in claim 1, comprising an insulating partition disposed in said housing at substantially right angles to said bracket, said active terminal being supported on said partition,

3. In a fused outlet device, a housing open at one end thereof, active and neutral terminals in said housing, a member mounted on and closing the open end of said housing, said member including a sleeve adapted to receive a contact element of an electrical appliance to be connected to said outlet, a fuse to transmit current not exceeding a predetermined value from said active terminal to a contact element introduced into said sleeve, said fuse being disposed inaccessibly in said housing rearwardly of said closing member when the latter is in its place and means for locking said housing and closing member together to prevent tampering with said fuse.

WILLIAM JAMES PETER STONEI-IOUSE, 

